36 



BULLETIlSr 1090, U. S. DEPARTMENT OF AGRICULTURE. 



Table 19. — The average birth weight in grams of young raised to 33 days. Control 

 stock by years, 1911 to 1920. 









[The 



average in each size of litter and the index, as in Table 7.] 









Year. 



Size of litter. 



In- 

 dex. 



Year. 



Size of litter. 



In- 



1 



2 



3 



4 



5 



6 



1 



2 



3 



4 



5 



6 



dex. 



1911.. 

 1912.. 

 1913.. 



99.5 

 110.7 

 111.2 

 117.8 

 100.1 



93.6 

 96.2 

 96.6 

 103.7 

 95.1 



80.2 

 88.5 

 83.0 

 85.5 

 84.5 



69.3 

 73.7 

 70.1 

 77.8 

 69.8 



65.1 

 67.9 

 64.2 

 72.7 

 64.5 



62.0 

 63.6 

 63.0 

 63.2 

 59.5 



84.0 

 90.1 

 87.3 

 92.7 

 86.3 



1916.. 

 1917.. 

 1918.. 

 1919.. 

 1920.. 



108.5 

 105.2 

 117.4 

 113.1 

 118.9 



88.7 

 86.8 

 91.3 

 97.9 

 95.9 



73.1 

 73.0 

 73.8 

 80.9 

 83.4 



64.5 

 63.5 

 71.9 

 72.2 

 72.1 



53.7 

 64.5 



59.5 



79.6 



78.5 

 83.0 



1914. . 

 1915.. 



65.6 

 63.2 



60.1 

 61.2 



87.5 

 88.4 



Table 20. — The average gain between birth and 33 days, in grams. Control stock by 



years, 1911 to 1920. 



[The average in each size of litter and the index, as in Tahle 7.] 



Year. 



Size of litter. 



In- 

 dex. 



Year. 



Size of litter. 



In- 



1 



2 



3 



4 



5 



6 



1 



2 



3 



4 



5 



6 



dex. 



1911.. 

 1912. . 

 1913 



195.0 

 168.8 

 190.0 

 198.4 

 160.5 



141.5 

 178.3 

 175.5 

 201.5 

 171.0 



136.7 

 164.4 

 135.9 

 167.9 

 131.1 



127.8 

 120.4 

 128.8 

 143.2 

 114.4 



92,6 

 139.7 

 109.3 

 114.0 



94.8 



120.0 

 112.9 

 103.4 

 130.8 

 95.0 



142.2 

 160.2 

 151.8 

 176.0 

 142.7 



1916.. 

 1917.. 

 1918.. 

 1919.. 

 1920. . 



173.0 

 170.0 

 193.0 

 185.0 

 218.1 



137.2 

 1.52.7 

 168.7 

 180.6 

 182.2 



102.0 

 129.8 

 135.0 

 147.8 

 161.3 



96.6 

 98.1 

 139.8 

 133.5 

 147.1 



102.5 

 90.7 



130.0 



118.6 

 134.3 

 151 9 



1914. . 

 1916. . 



112.8 

 123.7 



113.8 

 120.6 



158.5 

 170.4 



Table 21. — The average lueight at 33 days, in grams. Control stock by years, 1911 to 1920. 

 [The average in each size of litter and the index, as in Table 7.] 



Year. 



Size of litter. 



In- 

 dex. 



Year. 



Size of litter. 



In- 



1 



2 



3 



4 



5 



6 



1 



2 



3 



4 



5 



6 



dex. 



1911.. 

 1912.. 

 1913.. 



294.5 

 279.5 

 SOL 2 

 316.2 

 260.6 



235.1 

 274.5 

 272.1 

 305. 2 

 266.1 



216.9 

 252.9 

 218.9 



197.1 

 194.1 

 198.9 



157.7 

 207.6 

 173.5 

 186.7 

 159.3 



182.0 

 176.5 

 166.4 

 194.0 

 154.5 



226.2 

 250.3 

 239.1 

 268.7 

 229.0 



1916.. 

 1917.. 

 1918.. 

 1919.. 

 1920.. 



281.5 

 275.2 

 310.4 

 298.1 

 337.0 



225.9 

 239.5 

 260.0 

 278.6 

 278.1 



176.1 

 202.8 

 208.8 

 228.7 

 244.7 



161.1 

 16L6 

 211.7 

 205.7 

 219.2 



156.2 

 155.2 



189.5 



198.2 

 212.8 

 234 9 



1914.. 

 1915.. 



253.4 

 215.6 



221.0 

 184.2 



178.4 

 186.9 



173.9 

 171.7 



246.0 

 258.9 



Table 22. — The number of males and females and the sex ratio {males per 100 females). 

 [Inbred and control stocks by years, 1906 to 1920.] 





Inbred stock. 



Control stock. 





Inbred stock. 



Control stock. 















i 







i 







i 

























































03 









a 







a 

















Year. 





i 



"3 



8 



0) 







i 



Year. 







8 

 Si 







8 





i 





i 



-a 

 a 



a. 







"3 



a 



a 



i 



0) 



-3 



p. 





-3 



■a 



"3 



■3 





^ 



-3 



■3 



3 



■3 





% 



f^ 



s 



S 



p^ 



S 





S 



fi< 



% 



1^ 



f^ 



S 



1906 



37 



343 



806 



1,335 



1,919 



1,188 



35 

 333 



855 

 1,223 

 1,922 

 1,158 



105.7 

 103.0 



94.3 

 109.2 



99.8 

 102.6 









1015 



1916 



1917 



1918 



1919 



1920 



1,129 

 894 

 498 

 341 

 556 

 704 



1,051 

 879 

 480 

 329 

 504 

 711 



107.4 

 10L7 

 103.8 

 103.6 

 110.3 

 99.0 



191 

 223 

 209 

 151 

 178 

 255 



211 

 223 

 199 

 153 



187 

 209 



90.5 



1907 









100.0 



1908 









105.0 



1909 









98.7 



1910 









95.2 



1911 



155 



143 



108.5 



122.0 



1912 



1913 



1,135 

 1,051 



1,119 

 991 



10L4 

 106.0 



176 

 239 



160 

 199 



110.0 

 120.1 

















Total.... 



12,831 



12,529 



102.4 



2,051 



2,007 



102.2 



1914 



895 



939 



95.3 



274 



323 



84.8 

















